Increased concern is being given to non-point source pollution which originates from automobile fluids leaked onto pavement, such as parking surfaces and subsequently carried by contaminated, surface heated rainwater into sensitive creeks and streams. Of additional concern is the increased amount of impermeable surfaces in urban areas which limit groundwater infiltration and increase velocities of runoff, thereby damaging under-sized storm water conveyance infrastructure. Also of concern is the steady increase in non-porous black asphalt parking surfaces which increase air temperatures and add to global warming.
The present invention relates to a high strength porous pavement structure that actively filters out hydrocarbon pollutants from Stormwater, and is capable of holding the filtered water in a lower layer of recycled glass. Water carrying hydrocarbons that penetrates an upper wearing course flows into a hydrocarbon-adsorbent recycled glass layer (filtration/water storage layer).
Current technology in porous pavements is limited to using mostly virgin construction materials and does not actively filter hydrocarbons from the Stormwater prior to entering the underground aquifers. While the EPA encourages the use of porous pavements in their 1999 EPA fact sheet 11, “Porous Pavements”, they express concern of using the current technology over aquifers due to potential risk of contamination from oil and grease that can be leaked from vehicles. The present invention defuses this concern by providing a porous pavement composition and structure that is able to remove hydrocarbons from water that passes therethrough so that underlying aquifer water quality is maintained.
The present invention utilizes recycled glass which is abundantly recycled, but has few commercial uses, diverting large volumes of glass from landfills. The recycled glass when mixed with aggregate and binder, creates a strong, attractive parking surface. The recycled glass actively adsorbs hydrocarbons while removing said hydrocarbons from polluted Stormwater before it enters underground aquifers. In addition to this environmental benefit, the porous parking surface will reduce flooding and promote groundwater recharge and allow for more efficient use of urban parking areas. The reflective nature of glass will also help keep the parking surface cool, reducing the urban heat island effect.
Increased water quality awareness and desire to use Green building materials make the glass, aggregate and binder composite composition unique and attractive to environmentally conscious builders. Many state and federal governments are requiring the use of building products that offer Leadership in Energy and Environmental Design (LEED) points as regulated by the United States Green Building Council (USGBC) on municipal building projects. The present invention will rate higher in LEED points than any current porous pavement technology allowing architects and owners to achieve Gold and Platinum LEED standards more easily.